Seal

ABSTRACT

The invention relates to a lock comprising a housing ( 5 ) and a strap ( 1 ) that has a first end ( 2 ) and a second end ( 6 ), said housing ( 5 ) comprising: means ( 4 ) for securing the first end ( 2 ) of the strap ( 1 ); an interior cavity ( 40 ); a first ( 7 ) and a second ( 8 ) opening that give access from the exterior to said cavity ( 40 ), and allow advancement through the housing ( 5 ) of the second end ( 6 ) of the strap ( 1 ); a first interior, longitudinally extending wall ( 9 ) and a second opposed, interior, longitudinally extending wall ( 10 ), said walls extending between said first and second openings; a locking device ( 14 ) arranged within the cavity ( 40 ) between the first ( 9 ) and the second ( 10 ) walls and that defines a nipping area ( 45 ) for securing the second end ( 6 ) of the strap ( 1 ); and support areas ( 50 ) for the strap ( 1 ) whereby turning of the strap ( 1 ) about its longitudinal axis is prevented. The invention is characterised in that the strap ( 1 ) is a string of a plastics material ( 110 ) having a polygonal cross section; and that the locking device ( 14 ) has a surface that is toothed and/or rough.

The present invention relates to a lock as described in the preamble toclaim 1 and comprising a housing and a pull absorbing strap.

[0001] U.S. Patent disclosure No. 4,074,916, incorporated herein byreference, teaches such lock wherein the strap is constituted by a wireor a cable. In this patent it is described how safety is increasedagainst a person being able to release the lock by pulling the wirewhile simultaneously the wire is turned or rotated about itslongitudinal axis. In this prior art lock, the locking device for thewire is a disc that is—by means of a spring fitted in the cavity betweenthe sidewalls of the housing—pressed against the entry openings for thefree end of the wire. Hereby the spring ensures that the disc willalways wedge securely in order to tightly nip in the wire if it isattempted to pull out the wire through the entry opening. If,conversely, the wire is pulled in the opposite direction—out through theexit opening for the wire, the spring yields and the wire is able topass freely. When thus the one end of the wire is secured in the lockhousing and the opposite end is pulled through the housing, a closedwire loop is obtained that cannot be opened, but only be tightened.Locks of this type are used for a variety of sealing purposes, eg forsealing of large transport containers. Once the lock has been tightenedit cannot be removed unless the wire or the lock is damaged.

[0002] The U.S. patent disclosure teaches that, in advance, the wire orthe cable has been pressed flat to bring about an oval cross section.Besides the lock housing is provided interiorly with such configurationthat said turning or rotation of the wire becomes difficult, the housingalong with the disc forming support areas intended to prevent suchturning. Albeit the U.S. patent disclosure does not mention the wireconfiguration in detail, it seems, however, that it is the case of aconventional wire formed by helical winding of a number of metal wires.In order to accomplish said oval cross section, a difficult pressingoperation is thus required that uses a complex pressing tool.

[0003] It is the object of the present invention to provide an improvedlock that is both reliable and inexpensive and that does not presupposeinitial flat-pressing of a wire. The lock being a disposable device soldin large numbers, even a minor reduction in the production costs isimportant, and thus the invention makes it possible to eliminate theneed for a complex pressing tool.

[0004] This is obtained by a lock of the kind described above, whereinthe strap is a string of a plastics material and having a polygonalcross section. Besides, particularly advantageously the locking devicecan have a toothed or/and rough surface. This also means that it ispossible, in a simple manner, to ascertain visually whether attemptshave been made to break the lock, since such attempt will translate intodamage to the strap surface. “Polygonal” as used herein designates botha convex and a concave polygon, while it is expected, however, that astring with a convex polygonal cross section will be simpler tomanufacture. The string can, in cross section, have sides of equal sizeand the string can, in cross section, have slightly rounded corners.

[0005] The housing and the locking device can, in a conventional manner,be configured as featured in claim 2 where the housing has an interior,sloped wall that forms a guide for the locking device that is preferablyconfigured for being able to roll along this wall.

[0006] The support areas of the housing can be formed in a variety ofways, including the way featured in claim 3, by the entry opening forthe strap having a cross section that is complementary with thepolygonal cross section of the strap. Preferably, in the nipping areafor the strap, an interior wall in the housing may be provided with atrack shaped in accordance with the cross section of the strap.Advantageously it can be a ridged indentation whereby a portion of thestrap can be received in the guide between the wall and the lockingdevice and secured against said turning when the strap is oriented by anipping force oriented perpendicular to axial direction and exerted bythe locking device. It will be understood that in that case the supportface of the locking device will constitute a part of the support areasthat serve to prevent turning.

[0007] Particularly advantageously the strap can be reinforced, eg withfibres that are distributed in the plastics material or by a central,longitudinally extending core of metal that can be manufactured in aconventional manner by twisting of metal wires. In that event the strapcan advantageously be manufactured by extrusion.

[0008] The entry opening, ie the first opening of the housing, and theexit opening, ie the second opening of the housing, for the strap asfeatured in claim 10 having particular linear guides for the strap, itis possible to apply to the strap, during its advancement through thecavity within the housing, to a resilient flexing, the upwardly orientedmomentum of which urges the strap towards the locking device.

[0009] Hereby it is thus ensured that the locking device will, by anymovement of the strap towards the entry opening, be firmly wedgedbetween the strap and the sloping wall. Simultaneously it is possible toaltogether omit a separate resilient body, the resilient effect of aslightly flexed strap being used to ensure a nipping force between thelocking device and the strap. This effect is obtained in the linearguides being, at the entry and/or exit opening (5), oriented towards onesurface of the locking device. Hereby it is ensured that the strapcannot pass through the cavity of the housing from the entry opening tothe exit opening without having to flex. U.S. Pat. No. 3,770,307 teachesa corresponding solution.

[0010] As featured in claim 11 the locking device can conveniently be asubstantially circular metal disc or roller with the rough or toothedsurface along the circle periphery. Such locking device is extremelysimple to manufacture.

[0011] In accordance with an embodiment according to claim 12, thelinear guide of the entry directs the strap towards a tangent of thelocking device and the linear guide of the exit directs the straptowards a chord of the locking device.

[0012] In accordance with an embodiment according to claim 13, the lockis particularly simple to manufacture.

[0013] Additionally, the lock may conveniently be configured as featuredin claim 14. Hereby a high degree of symmetry is accomplished which isadvantageous from a technical production point of view and, besides, itis possible for the end user himself to mount the first end of the strapin the lock.

[0014] In the following, an embodiment of the lock is described infurther detail with reference to the drawing, wherein

[0015]FIG. 1 is a perspective sectional view through a lock according tothe invention;

[0016]FIG. 2 is a planar sectional view through a central plane in thelock shown in FIG. 1;

[0017]FIG. 3 is a sectional view through the lock along the line B-B inFIG. 2; and

[0018]FIGS. 4a-4 show enlarged sections of FIG. 3.

[0019] The lock according to the invention comprises a housing 5 and aflexible strap 1. The strap 1 has, as shown (FIG. 2), a first end 2intended for being conveyed through an entry opening 3 in the housing 5and for being secured to the housing 5 before the lock is taken intouse. In the embodiment shown the securing of the end 2 is accomplishedby means of a movable locking device 14′, but other means of securingare possible. Thus the first end 2 of the strap 1 can be cast or nippedfirmly within the housing 5.

[0020] In accordance with the invention shown the strap 1 is a flexiblestring manufactured from a plastics material, and the strap 1 has—inthis example—a square cross section with lateral portions 1′. The strap1 has a tensile strength that is, during manufacture, adjusted inaccordance with the intended use of the lock. The tensile strength canoptionally be increased by reinforcing the string, but it is within thescope of the invention to use a string that is made exclusively ofplastics.

[0021] The opposite end 6 of the strap is conveyed through or around thebody (not shown) that is to be secured and through the housing 5 via anentry opening 7 and an exit opening 8. The openings 3, 7 and 8 give, aswill appear, access to an interior cavity 40 within the housing 5.

[0022] In the cavity 40 there are, between the openings 7 and 8,arranged two walls 9 and 10, of which the wall 9 extends substantiallyalong the longitudinal axis of the housing and in direct extension ofthe opening 7. The sidewall 10 has a sloping course whereby the distancebetween the two walls is reduced in a direction towards the opening 7. Adisc or roller shaped lock device 14 is situated within the housing 5between the sidewall 10 and the strap 1, and when it is attempted topull the strap 1 out through the entry opening 7, the lock device 14will roll along the wall 10 and wedge firmly between the wall 10 and thestrap whereby the further movement of the strap 1 in that direction isprevented.

[0023] Both openings 7 and 8 have linear guides for the strap 1, suchthat the orientation of the strap 1 into the housing is controlled. Thelinear guide at the opening 7 leads the strap in the longitudinaldirection of the housing 5 and along the wall 9, and the linear guide atthe opening 8 conveys the strap in the longitudinal direction of thehousing, but is slightly offset relative to the entry 7. Thereby thestrap is conveyed towards a chord of the locking device 14. In order topass from the entry opening 7 to the exit opening 8 and around thelocking device 14, the strap will have to flex. Such flexing will occuras a consequence of the strap be being resilient. It is noted that thiseffect can be achieved both by use of the strap of plastics material inaccordance with the invention and by use of a wire that is not coated bya plastics jacket.

[0024] As mentioned, the locking device 14 is a round disc or rollerthat has, along its periphery, a toothing or is rough. The resilientabutment of the strap 1 on the periphery of the disc or roller and therough surface will cause the roller or disc to roll upwards on the face10, if attempts are made to pull the strap out through the entry opening7, whereby the strap is wedged firmly against the face 9 due to thesloped course of the face 10. Thereby it is ensured that once it hasbeen conveyed out through the opening 8, the strap cannot be withdrawn.A corresponding mechanism is used to withhold the first end 2 of thestrap within the housing. Only in that case there is no exit,but—conversely—a blind hole 18 down into which the strap is conveyed.The linear guides, the sidewalls 9′ and 10′ at the entry 3, and thelocking device 14′ are configured in the same manner as was the casewith the through-going opening.

[0025] In the embodiment shown the housing. 5 comprises a jacket 11 andan insert 12. The insert 12 matches into the jacket 11 and is securedtherein by a snap locking connection 13. Conveniently the jacket is madeof plastics and the insert of metal or plastics that can optionally bereinforced, but other material combinations are possible. The lockingdevices 14 and 14′ are preferably made of metal. As will appear from thefigure, the walls 9 and 10 and the entries 3 and 7 are configured withassociated guides for the insert 12, and the jacket forms the exit 8 andthe blind hole 18 with associated guides.

[0026]FIG. 1 shows a part of the housing 5 at the opening 7. It willappear that in this area the opening 7 is configured with a crosssection that is complementary to the cross sectional shape of the strap1, ie in the case shown preferably with a square cross section and aclearance width that corresponds approximately to the dimensions of thestrap 1, whereby turning of the strap 1 about its longitudinal axisoutside the housing will not give rise to a corresponding turning ofthat part of the strap 1 that is situated within the housing 5. Thesides 7 of the openings thus form a support area 50 for the strap inthis region.

[0027] Now FIG. 2 shows how the housing 5 can comprise further supportareas 50 intended for preventing a rotation of that part of the strap 1that is situated within the housing 5. More specifically, these supportareas are located at the nipping area 45 for the strap 1, ie in the areawhere the strap 1 can be firmly nipped between the locking device 14 andthe wall 9. The support area 50 is in this case defined by the surfaceof the locking device 14 and by the surface of the wall 9. FIGS. 4a-eshow enlarged sections of FIG. 3 that show a cross section between thehousing 5 at the nipping area 45. FIGS. 4a-e show alternative crosssectional shapes for the strap 1, and it will appear that the strap 1 isconfigured with a polygonal cross section with preferably three, four,five or six sides. As will appear the strap 1 is configured as a stringof a plastics material 110 that is, in the embodiment shown, reinforcedwith a number of longitudinally extending, twisted metal wires 100. Itwill appear from FIGS. 4a-d that the wall 9 can be provided with a track47 that is dimensioned to be able to receive a portion of the crosssection of the strap 1. Preferably the opening 7 is configured such thatthe strap 1 is automatically aligned to a correct position in order tobe receivable in the track 47. Preferably the track 47 has, as willappear, side edges that meet in angles corresponding to the polygonalcross section of the strap 1. However, the track 47 is not an absolutenecessity, since the wall 9 may very well be planar as shown in FIG. 4e.However, it is of importance that the wall 9 and the locking device 14are configured and adjusted in accordance with the cross sectional shapeof the strap 1 so as to establish support areas 50 that prevent thestrap 1 from turning.

1. A lock comprising a housing (5) and a strap (1) that has a first end(2) and a second end (6), said housing (5) comprising: means forsecuring the first end (2) of the strap (1 ); an interior cavity (40); afirst (7) and a second (8) opening allowing advancement through thehousing (5) of the second end (6) of the strap (1); a first interior,longitudinally extending wall (9) and a second opposed, interior,longitudinally extending wall (10), said walls extending between saidfirst and second openings; a locking device (14) arranged within thecavity (40) between the first wall (9) and the second wall (10) and thatdefines a nipping area (45) for securing the second end (6) of the strap(1); and support areas (50) for the strap (1) whereby rotation of thestrap (1) about its longitudinal axis is prevented, characterised inthat the strap (1) is a string of a plastics material (110) having apolygonal cross section and cooperating with said support areas (50) forpreventing said rotation, said string of plastics material (110) beinginternally reinforced, that the strap (1) is manufactured by extrusion,and that the locking device (14) is a substantially circular metal discor roller with a rough or toothed surface arranged along the circleperiphery.
 2. A lock according to the preceding claim, characterised inthat that locking device (14) is configured for being movable in adirection towards the first opening (7); and that the second wall (10)has a sloped course relative to the first wall (9) whereby the distancebetween the first (9) and the second (10) walls is reduced in adirection towards said first opening (7) thereby defining the nippingarea (45) between the first wall (9) and the locking device (14).
 3. Alock according to any one of the preceding claims, characterised in thatthe first opening (7) has a cross section that is complementary with thepolygonal cross section of the strap (1) for forming said support areas(50) for preventing axial rotation of the strap (1).
 4. A lock accordingto the preceding claim, characterised in that the first wall (10) is, atleast at the nipping area (45), provided with a track (47) that extendsalong the strap (1) with support areas (50) for the strap (1) in orderto combine with the locking device (14) to secure the strap (1) againstsaid axial rotation.
 5. A lock according to the preceding claim,characterised in that the track (47) has sidewalls (50) configured forbeing able to abut on lateral portions (1′) of the strap (1).
 6. A lockaccording to any of the preceding claims, characterised in that thereinforcement of the plastics material (110) is constituted by a wire(100) formed by twisted metal wires.
 7. A lock according to any of thepreceding claims 1-5, characterised in that the reinforcement of theplastics material (110) is constituted by fibres distributed in theplastics material (110).
 8. A lock according to any one of the precedingclaims, characterised in that the first (7) and the second (8) openingshave linear guides for the strap (1), the linear guide of the secondopening (8) being oriented towards a surface of the locking device (14)whereby the band (1) will, by the advancement through the cavity (40),be exposed to a resilient flexing, the upwardly oriented moment of whichpressing the strap (1) towards the locking device (14).
 9. A lockaccording to the preceding claim, characterised in that the linear guideof the first opening (7) directs the strap along a tangent of the metaldisc or roller (14); and the linear guide of the second opening (8)directs the strap towards a chord of the metal disc or roller (14). 10.A lock according to any one of claims 8 or 9, characterised in that thehousing (5) comprises a jacket (11) with the second opening (8) and itsassociated linear guide, and an insert (12) configured for beingsealingly displaceable into the jacket (11) and secured therein with asnap connection (13), said insert (12) inwardly defining the first (9)and the second (10) walls, wherein the insert (12) is—in the end portionthat faces away from the jacket (11)—provided with the first opening (7)with its linear guide.
 11. A lock according to any one of the precedingclaims, characterised in that the housing (5) comprises a third opening(3) that gives access to said cavity (40) and allows introduction intothe housing (5) of the first end (2) of the strap (1); that the cavity(40) comprises a third longitudinally extending wall (9′) and an opposedfourth, longitudinally extending wall (10′), said walls extending fromsaid third opening (3), wherein the fourth wall (10′) has a slopingcourse relative to the third wall (9′) whereby the distance between thethird (9′) and the fourth (10′) walls is reduced in a direction towardssaid third opening (3); and that the means for securing the first end(2) of the strap (1) are in the form of a movable locking device (14′)arranged in the cavity (40) between the third (9′) and the fourth (10′)sidewalls in order to combine with the third wall (9′) to define anipping area for securing the first (2) end of the band (1).